It is typical for elevator systems to include a door lock mechanism on hoistway doors. The door lock mechanisms on the hoistway doors prevent the hoistway doors from being opened when the elevator car is not at a landing. A majority of the hoistway door locking mechanisms are mechanical and include multiple rollers and moving parts. Such door locking mechanisms require frequent adjustments and are a cause for many callbacks.
In recent years, elevator codes have required locking devices for preventing elevator car doors from opening when the elevator car is not within the door zone. Existing door locks for the elevator car doors are similar to locks used for the hoistway doors and are primarily mechanical. The elevator car door locks also require cumbersome installation procedures and frequent adjustments. Additionally, in the event of failure of the door lock, the elevator controller is not aware of failure.
Another major concern in elevator car door locking mechanisms, besides reliability and adjustability problems, is noise level. Noise is a concern since the door locking mechanism should not be noticeable to the occupants of the elevator car. Power consumption of the door lock is another consideration in designing door locks.